Disk drive with compensation of disk eccentricity

ABSTRACT

A device for rotating inside of a disk player and/or recorder a disk shaped data carrier which takes into account that the rotating disk may be eccentered from an imposed rotation axis. Side moving means allow the rotating disk and the fixing means to which the disk is removably fixed, to move inside said player and/or recorder in a rotation plane substantially perpendicular to an axis of rotation of said fixing means. The rotating disk and the fixing means go into a gyroscopic movement inside the player. A plurality of examples to realize the invention are described.

BACKGROUND OF THE INVENTION

The present invention relates to a device used for rotating disk shapeddata carriers inside of disk player and/or recorders.

A disk player and/or recorder is used to read and/or write on diskshaped data carriers. Different types of disk shaped data carriers areknown, e.g. magnetical and optical disk shaped data carriers. Data maybe stored along tracks which form for example concentrical circles or aspiral on the disk shaped data carrier. The disk shaped data carrierstypically have an opening at a center, which ideally has substantially acommon center with the disk shaped data carrier and the concentricalcircles or the spiral. The disk shaped data carrier is rotated bydriving means which are linked directly or indirectly to its opening,i.e. the driving means' rotation axis is made to correspond with thecenter of the disk. The data is read using reading means which followthe track. A servo system determines if the reading means deviate fromthe track being followed and if necessary move the reading means toreposition them on the track. The better the driving means' rotationaxis corresponds to the center of the disk, the better the concentricalcircles or spiral rotate around their own center and the less the servosystem has to correct deviations to compensate for an eccentricity ofthe concentrical circle's or the spiral's rotation.

A data reading and/or writing rate of a disk player and/or recorderdepends for a part on a disk's rotation speed. The reading and/orwriting rate may for example be increased with a higher rotation speedof the disk. Typically a new problem arises in the disk player and/orrecorder at higher rotation speeds. The player and/or recorder starts tovibrate, become more noisier and eventually to generate a greater numberof reading and/or writing errors because the servo system may notanymore keep the reading means on track.

One reason for the new problem lies in the mass distribution of the diskshaped data carrier and parts fixed to it during its rotation. Moreprecisely a mass center of the disk shaped data carrier and parts fixedto it may be located aside of the rotation axis imposed by the drivingmeans and, as a result, the rotation of the disk generates forces whichdraw the disk away from the imposed rotation axis. The displacement ofthe mass center can be caused by labels on the disk, imperfectmanufacturing of the disk, erroneous centering of the opening or otherreasons. But it may also be related to the disk player and/or recorderitself.

A known solution to overcome the problems related to higher rotationspeeds is to reduce the rotation speed until an acceptable level ofnoise, vibration and/or number of reading/writing errors is achieved.This of course reduces the data reading and/or writing rate.

SUMMARY OF THE INVENTION

It is an object of the present invention to find a device which allowsto overcome the problems due to higher rotation speeds of the diskshaped data carrier.

The invention provides a device for rotating inside of a disk playerand/or recorder a disk shaped data carrier having an opening around acenter of the disk shaped carrier. The device comprises at least fixingmeans which allow to removably fix the disk by inserting a part of thefixing means in the opening and driving means which rotate the datacarrier by acting on the fixing means. The driving means are at leastpartly mechanically connected to the disk player and/or recorder. Thedevice further comprises side moving means which allow the fixing meansto move inside the disk player and/or recorder in a rotation planesubstantially perpendicular to an axis of rotation of the fixing means.

The fixing means move together with the disk inside the disk drive in aplane which has substantially a same orientation as centrifugal forcesacting on a center of mass of a disk fixing means assembly which islocated aside from a rotation axis of the fixing means imposed by thedriving means. The vibrations on the disk player and/or recorder arereduced.

In a first preferred embodiment of the invention according to theinvention the side moving means comprise sliding means which allow tomove the driving means inside the player and/or recorder alongdirections which are parallel to the rotation plane and elasticalelongation means fixed at one end to the player and/or recorder and atanother end to the driving means, such that the driving means arepositioned in a determined rest position at least when the driving meansstop driving the data carrier.

An advantage of the preferred embodiment is that the fixing means may bemounted rigidly on e.g. a driving shaft of the driving means thusallowing for a very simple connection between driving means and fixingmeans.

In a second preferred embodiment according to the present invention theside moving means further comprise flexible transmission means throughwhich the driving means act on the fixing means. An end of the flexibletransmission means is connected to the driving means and another end isconnected to the fixing means.

The second preferred embodiment allows to move the fixing meansindependently from the driving means. An advantage of this is that themoved mass is less than is if the driving means were to be moved aswell.

In a third preferred embodiment according to the present invention theside moving means comprise first bearing means which are mounted on thefixing means, and the disk and/or recorder comprises at least asupporting surface parallel to the rotation plane, such that the firstbearing means allow the fixing means to slide on the supporting surfacewhile the fixing means rotate.

The third preferred embodiment shows a simple solution to realize amovement of the fixing means in the player and/or recorder.

In a fourth preferred embodiment according to the present invention themoving means comprise a sliding support and the disk and/or recordercomprises at least a supporting surface being parallel to the rotationplane; the sliding support slides on the supporting surface and thesliding support has a drive opening through which the driving means acton the fixing means.

The fourth preferred embodiment is particularly advantageous to reducethe intensity of friction between the moving means and the supportingsurface since only the fixing means are driven and rotated by thedriving means, i.e. the moving means do not have to rotate in the sameway as the fixing means.

In a fifth preferred embodiment according to the present invention theside moving means comprise a sliding support having a drive openingthrough which said driving means act on said fixing means. The diskand/or recorder comprises at least a supporting surface which isparallel to the rotation plane, such that the sliding support slides onthe supporting surface. In the device, at least an elongated part of thefixing means is fitted through the drive opening together with secondbearing means which allow the elongated part to rotate inside the driveopening. The driving means comprise a rotor magnet mounted on theelongated part and a stator electro-magnet mounted on the player and/orrecorder such that the rotor magnet and the stator electro-magnetcooperate as an electric motor. The device further comprises centeringmeans which position the fixing means in a central position at leastwhen the driving means stop driving the data carrier.

The fifth preferred embodiment allows to minimize a weight and size ofthe device according to the invention.

The invention further provides a device for rotating inside of a diskplayer and/or recorder a disk shaped data carrier having an openingaround a center of the disk shaped carrier, the device comprising atleast fixing means which allow to removably fix the disk by inserting apart of the fixing means in said opening, and driving means which rotatethe data carrier by acting on the fixing means. The driving means are atleast partly mechanically connected to the disk player and/or recorder.The fixing means comprise an elongated part; the driving means comprisea rotor magnet which is mounted on the elongated part and a statorelectro-magnet mounted on said player and/or recorder such that therotor magnet and the stator electro-magnet cooperate as an electricmotor. The device further comprises centering means which position thefixing means in a central position at least when the driving means stopdriving the data carrier.

The latter device for rotating inside of a disk player and/or recorder adisk shaped data carrier according to the invention is a mechanicallysimple and cheap way of realizing the invention.

The invention even further provides a device for rotating inside of adisk player and/or recorder a disk shaped data carrier having an openingaround a center of said disk shaped carrier, which comprises at leastfixing means allowing to removably fix the disk by inserting a part ofthe fixing means in the opening, and driving means for generating adriving force to rotate the data carrier. The driving means are at leastpartly mechanically connected to the disk player and/or recorder andcomprise compressor means to generate a stream of air and canalizationmeans to direct the stream of air onto a surface which belongs to thedata carrier and/or the fixing means such that a driving force istransmitted to the data carrier which sets the data carrier intorotation and such that an air cushion lifts the data carrier and thefixing means reducing mechanical friction between the fixing means andthe driving means. The device further comprises centering means whichposition the fixing means in a central position at least when thedriving means stop driving the data carrier.

The latter device according to the invention is particularlyadvantageous because it reduces sources of frictions.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, ways of carrying out the invention claimed will bedescribed using examples and referring to the drawings wherein:

FIG. 1 contains a schematical drawing of a player and/or recorderaccording to prior art,

FIG. 2 contains a schematical isometrical representation of a deviceaccording to the invention and comprising elastical elongation means,

FIG. 3 contains a schematical representation of a device according tothe invention comprising sliding fixing means,

FIG. 4 contains a schematical representation of a device realizedaccording to the invention and comprising a sliding support,

FIG. 5 contains a schematical representation of a device realizedaccording to the invention comprising a sliding support,

FIG. 6 contains a schematical representation of an advantageousembodiment of a device according to the invention,

FIG. 7 contains a schematical representation of a device according tothe invention in which the data carrier levitates,

FIG. 8 shows a schematical representation of a device according to theinvention which comprises pneumatical driving means,

FIG. 9 contains an explanatory drawing to visualize an action of astream of air in FIG. 8,

FIG. 10 shows a schematical representation of a pneumatically drivendevice according to the invention,

FIG. 11 contains a schematical representation of a device according tothe invention which comprises pneumatical driving means.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

All through the specification same references will be used to designatesame parts. It is understood that the examples described hereafter aregiven to better understand the invention and are not limitative of theclaimed invention. A person skilled in the art may well modify thedescribed examples and remain in the scope of the present invention.

FIG. 1 contains a schematical representation of a disk player and/orrecorder according to prior art. More precisely the example shown inFIG. 1 is an optical disk player and/or recorder seen in a sideviewplane which is perpendicular to a disk shaped data carrier 1. The diskshaped data carrier 1, i.e. an optical disk has an opening 2 at itscenter. The data carrier 1 has data stored along tracks formed on alayer (not shown) of the data carrier 1. The data tracks formconcentrical circles or spirals on the disk and remain in a rotationplane which is perpendicular to the sideview plane of the figure. Theconcentrical circles or the spirals have a center which ideallycorresponds to a rotation axis 3 represented in FIG. 1 using a dotedline. Preferably geometrical centers of the data carrier 1 and of theopening 2 correspond to the center of the concentrical circles or thespiral, i.e. the latter centers lie on the rotation axis 3. Fixing meanscomprise a plate 4 which supports a surface of the data carrier 1, and apart 5 which is inserted into the opening 2 such that the data carrier 1is removably fixed to the fixing means 4 and 5. The part 5 of the fixingmeans may be a bobby well known by a person skilled in the art. Such abobby may for example have on its outer periphery a number of ballspushed away from the rotation axis 3 by springs (not shown) such tomaintain the data carrier 1 on the bobby. Driving means 6 are fixed tothe disk player 77 represented by a hat shaped block for reasons ofsimplicity. The driving means 6 may for example comprise an electricalmotor. An axis of the electrical motor is connected to rigidtransmission means 7 which transmit a rotation of the electrical motorto the fixing means 4 and 5. This way the driving means 6 act on thefixing means 4 and 5, and rotate the data carrier 1 around the rotationaxis 3.

The data stored along tracks on the data carrier 1 are read out usingreading means which comprise a light source 8, a mirror 9 forredirecting light from the light source 8 to the data carrier 1, andfocusing means 10 to focus the light beam on the data track being read.Light reflected by the data carrier 1 is detected by detection means 11in order to restitute data stored on the data carrier 1. The light beamis focused on the track being read in a light spot 12. A servo system(not shown) continually verifies if the light spot 12 remains on thetrack being read. In case of a deviation of the light spot from thetrack the servo system controls radial positioning means and focusingmeans (not shown) to re-position the light spot 12 in radial but also inheight direction, the latter corresponding to the direction of therotation axis 3. The positioning in radial and height direction isschematically represented by a double arrow 13.

Frequently a mass center (not shown) of the data carrier 1 and/or a masscenter of an assembly comprising the data carrier 1, the fixing means 4and 5 and perhaps the driving means 6, does not correspond to the centerdefined by the rotation axis 3. When the disk is rotated a centrifugalforce occurs which acts on the mass center, and tends to pull the datacarrier 1 away from the rotation axis 3. At relatively high rotationspeeds of the data carrier 1 the centrifugal force, which isasymmetrical relatively to the rotation axis 3 induces vibrations whichimpact on the disk player 77 and induce reading and/or writing errors inthe reading means, the latter not being able anymore to keep the lightspot 12 on the track being read.

The reading means shown in FIG. 1 are well known from a person skilledin the art and will for reasons of simplicity be omitted from thefollowing FIGS. 2 to 11.

The example described in FIG. 1 relates to an optical disk drive. It isunderstood that any other kind of disk drive, e.g. a magnetical or anopto-magnetical disk drive could also be used to explain the invention.Of course a person skilled in the art would then use adapted readingand/or writing means.

FIG. 2 contains a schematical isometrical view of a device for rotatingthe disk shaped data carrier 1 (shown in part only). The data carrier 1is fixed using fixing means 4 and 5 (shown in part only), the part 5being inserted into the opening 2. The driving means 6 act on the fixingmeans 4 and 5 through transmission means 7. The driving means 6 arefixed to a disk player 78 through elastical elongation means, e.g. afirst and a second spring 14 and 15. The driving means 6 lie on slidingmeans 16 which allows them to move in X and Y direction in the diskplayer 78. In a case where the driving means are at rest, i.e. thedriving means 6 do not act on the fixing means 4, 5, the springs 14 and15 keep the driving means 6 in a determined rest position.

As soon as the driving means 6 start to rotate the data carrier 1, theasymmetrical centrifugal forces which act on the eccentered mass centercause the springs 14 and 15 to elongate or shorten in X and Y directionrespectively. The rotation axis 3 around which the data carrier 1 andthe fixing means 4 and 5 are rotated remains parallel to the Z directionbut starts moving in circles around the determined rest position. Infact, an assembly comprising the data carrier 1, the fixing means 4 and5 and the transmission means 7 undergoes a gyroscopic movement. Novibration of the player 78 is caused by the movement of the assembly.The fact that the rotation axis 3 now describes circles around thedetermined rest position creates a periodic deviation of the data trackbeing read relatively to the reading means. This periodic deviationneeds to be corrected by the servo means.

A disk player 79 in FIG. 3 has the driving means 6 fixed to it in amanner similar as in FIG. 1. The disk player 79 comprises a platform 17which presents a supporting surface 18 to the fixing means' plate 4.First bearing means which may not be seen but who's location isindicated by an arrow 19 are located between the fixing means' plate 4and the supporting surface 18 and allow the fixing means 4 and 5, andthe data carrier 1 to slide on the disk player 79. The driving means 6act on the fixing means 4 and 5 through flexible transmission means 20which allows to transmit a rotation movement from the driving means 6 tothe data carrier 1 while the sliding means 4 and 5, and the data carrier1 are also allowed to move in Y and X direction. Centering means 21apply a force on the part 5 of the fixing means in order that the fixingmeans 4 and 5 remain in contact with the supporting surface 18.

The first bearing means in 19 must be realized such that the fixingmeans' plate 4 may rotate and slide sideways at the same time on thesupporting surface 18. The first bearing means 19 may for example berealized using a layer of grease or conventional ball bearings.

The centering means 21 comprises a conical recess 22 and is mounted onthe disk player 79 using a flexible bar 23. The centering means 21 arerealized such that the fixing means return to a central position whichcorrespond to the rest position of the rotation axis 3 when the drivingmean 6 are at rest. The flexible bar 23 enables the centering means 21to accompany the fixing means 4 and 5 during the gyroscopic movement.

Alternately it may be found that the fixing means 4 and 5 receive anedge 24 which grabs through a drive opening 25 of the disk playerplatform 17. In this case, the centering means 21 may be omitted becausethe edge 24 prevents the fixing means of departing from the supportingsurface 18 under the effect of the flexible transmission means 20.Preferably, the edge 24 is equipped with bearing means similar to thefirst bearing means in 19 such that the fixing means 4, 5 and the edge24 may freely slide and rotate on supporting surfaces of the platform17.

FIG. 4 shows a disk player 80 to which the driving means 6 are rigidlyfixed. A Sliding support 26 comprises edges 27 which allow to slide thesliding support 26 on supporting surfaces 18 of the disk player platform17. Second bearing means 28 allow the fixing means 4 and 5 to rotaterelatively to the sliding support 26 by means of an elongated part 29 ofsaid fixing means which passes through a drive opening 30 of the secondbearing means 28. The sliding support 26 merely slides in X or Ydirection. Compared to the disk player 79 shown in FIG. 3 the drivingmeans 6 in FIG. 4 need less work to rotate the data carrier 1 because noenergy losses occur through friction of the fixing means plate 4 on thedisk player 80.

Optionally centering means as shown in FIG. 3 may also be used in thedisk player shown in FIG. 4. The centering means position the fixingmeans to a central rest position at least when the driving means 6 rest.

FIG. 5 shows a disk player 81 which similar to the disk player 80 inFIG. 4 comprises a disk player platform 17 having supporting surfaces18. A sliding support 26 comprises edges 27 which allow to slide thesliding support 26 on the supporting surfaces 18. The fixing meanscomprise an elongated part 29 which is inserted in a drive opening 30 ofsaid sliding support 26 together with second bearing means 28. This waythe fixing means 4, 5 and 29 may rotate relatively to the slidingsupport 26. A rotor magnet 31 is fixed at an end of the elongated part29, and rotates together with the fixing means. The rotor magnet 31 ispart of driving means which further comprise a stator electro-magnet 32rigidly mounted on the disk player 81. The stator electro-magnet 32 isan electro-magnet which together with the rotor magnet 31 cooperates asan electric motor used to drive the fixing means and the data carrier 1.When the driving means are at rest the rotor magnet 31 is positionedbetween components of the stator electro-magnet 32 such that it isseparated from the latter by an air gap. The latter air gap allows therotor magnet 31 to adopt a gyroscopic movement when the fixing means 4,5, 29 and the data carrier are brought into high rotation speed. Thesliding support 26 allows the rotation axis 3 to rotate around a restposition of the rotation axis 3 while the data carrier 1 is rotatedaround the rotation axis 3. This way no vibrations due to the eccenteredmass center of the fixing means/data carrier assembly is transmitted tothe disk player 81.

Optionally, centering means similar to the one shown in FIG. 3 may beused in the disk player shown in FIG. 5. The centering means positionthe fixing means to a central rest position at least when the drivingmeans rest.

Optionally, limiting means (not shown) may be mounted on the platform 17or nearby a side of the centering means in order to limitate a sidewayssliding of the sliding support 26 and such to avoid a contact of therotor magnet 31 with the stator magnet 32.

FIG. 6 shows a disk player 82 in which the fixing means comprise anelongated part 33 fixed to the plate 4 and the part 5. The elongatedpart 33 is at one end terminated by a tip which lies on a point bearingrecess 34 integral to the player 82. Opposite to the tip end of theelongated part 33 the part 5 is terminated by another tip whichcooperates with a further point bearing comprised in the centering means21. Hence the assembly of the fixing means 4, 5, 33 and the data carrier1 rotates between two point bearings. The centering means 21 are furtherused to position the fixing means in a central rest position when theassembly stops rotating, and guide the fixing means while the latterassembly goes in a gyroscopic movement during its rotation around therotation axis 3. The fixing means and the data carrier 1 are driven bydriving means which comprise a rotor magnet 31 mounted on the elongatedpart 33, and a stator electro-magnet 35 which is mounted on the diskplayer 82. The stator electro-magnet 35 is an electro-magnet andcooperates with the rotor-magnet 31 as an electrical motor used torotate the fixing means and the data carrier 1. While the data carrier 1rotates around the rotation axis 3 and the assembly adopts thegyroscopic movement around the rest position of rotation axis 3, therotation axis 3 may also rotate around a point determined by the contactof the elongate part 33 and the point bearing 34. The latter rotation ofthe rotation axis 3 will cause a focus deviation in the reading means(not shown) which will have to be corrected by refocusing the light spotand the track being read.

FIG. 7 shows a simplified disk player 83 in which a part 5 of the fixingmeans is centered by annular centering means 36. An elastical bar 37allows to keep the annular centering means 36 in a central rest positionwhen the fixing means and the data carrier 1 are at rest. A rotor magnet38 mounted on edges of the plate 4 of the fixing means cooperates aspart of an electrical motor with a stator electro magnet 39 fixed on thedisk player 83. When the stator electro magnet 39 is provided withcurrent the rotor magnet 38 and thus the fixing means 4, 5 and the datacarrier 1 are forced towards the annular centering means 36 and startrotating. Air gaps between the rotor magnet 38 and the statorelectro-magnet 39 allow the rotating assembly to adopt a gyroscopicmovement around a rest position of the rotation axis 3.

In a preferred embodiment of the disk player 83 shown in FIG. 7 a pointbearing mounted at the rest position of rotation axis 3 on the staticelectrode magnet 39 allows the plate 4 of the fixing means to remain ata determined distance from the static electro-magnet 39 even when nocurrent is provided. The latter point bearing is not shown in FIG. 7.

FIG. 8 shows a disk player 83 which comprises pneumatical driving means.The data carrier 1 has edges of the plate 4 of the fixing means insertedinto its opening. The part 5 of the fixing means cooperates withcentering means 21 which allow to center the fixing means in a centralrest position at least when the data carrier stops rotating, and toguide the assembly of the fixing means and the data carrier in thegyroscopic movement while the data carrier 1 is rotated. Driving meanscomprise canalization means 40 which at one end receive a stream of air41 generated by compressor means 42. The stream of air 41 is splitted upby smaller canalization means 43 which terminate in nozzles 44 and 45.The nozzles 44 direct the stream of air 41 onto a surface 455 of thedata carrier 1 such to transmit to the data carrier 1 a force which setsthe data carrier 1 into rotation and a lifting force which keeps thedata carrier 1 at a determined height from the nozzles 44. The nozzles45 direct the stream of air at an outer periphery of a tube formed bythe canalization means and which is surrounded by a further tuberealized by the edges of the plate 4. The stream of air blowing out ofthe nozzles 45 pushes on a surface 46 of the edges of the plate 4 andprevents that the fixing means come in contact with the outer peripheryof the canalization means. The result is that during rotation of thedata carrier 1 and the fixing means 4, 5 an air cushion between thecanalization means and the rotating assembly minimizes friction andallows the rotating assembly to adopt a gyroscopic movement caused by aneccentered mass center of the rotated assembly. No vibrations aretransmitted to the disk player 84.

FIG. 9 shows a view of the device shown in FIG. 8 along a plane whichthrough is perpendicular to the plane of the FIG. 8. The view is takenthrough the data carrier 1 looking from the plate 4 of the fixing means(not shown) toward the canalization means. Four nozzles 44 aresymmetrically located around a rest position of the rotation axis 3represented by a black spot. The parts of nozzles 44 which are darklyfilled in the figure are the ones that are further away of the surface455 whereas the parts of the nozzles 44 which are filled with a crosslines patterns and the ones left empty respectively are nearer to thesurface 455. This way of illustrating the nozzles 44 shows that a streamofair coming from the darkly illustrated part to the empty illustratedpart of nozzles 44 blows in a direction represented by the arrow 466 andaccordingly creates a force on the surface 455 which rotates the datacarrier 1.

The nozzles 45 which end canalization means 43 are distributedsymmetrically at six points of the outer periphery of the canalizationmeans and direct the air stream of the inner surface 46 of the fixingmeans edges.

FIG. 10 shows a disk player 85 having another embodiment of pneumaticaldriving means. The part 5 of the fixing means is inserted in the openingof the data carrier 1 and once inserted a surface of the part 5 closesthe opening of the data carrier 1 and lies in the same plane as thesurface 455 of the data carrier 1. An output of the compressor means 42blows an stream of air 41 into canalization means 47. The stream of airis splitted into a plurality of nozzles 48, the latter beingsymmetrically positioned around a determined rest position of therotation axis 3. Centering means 21 comprising a conical recess 22 arefixed to an elastical bar 23 and position the fixing means in thedetermined rest position when the data carrier 1 is at rest. A sidewaysmovement of the elastical bar 23 is limited by the wall of a tube 49placed around the elastical bar 23 and fixed at one end to the diskplayer 85.

The nozzles 48 direct the stream of air on the surface 455 such to liftthe data carrier 1 and the fixing means 4, 5 by creating an air cushionbetween the latter and the disk player 85, and such to create a drivingforce on the data carrier 1 in order to rotate the latter at relativelyhigh speed. The assembly of the data carrier and the fixing means 4, 5starts to go into a gyroscopic movement around the rest position of therotation axis 3. No vibrations resulting from an eccentered mass centerof the assembly are transmitted to the disk player 85.

FIG. 11 shows a disk player 86 in which the driving means comprise afirst tube 50 into which a stream of air 41 is blown by compressor means42. The first tube 50 has openings at its periphery terminated by nozzle51. The first tube 50 has at another end an opening 52 through which apart of the stream ofair 41 blows. The fixing means comprise a secondtube 53 which at one end is fixed to the plate 4 and at another end asan opening which allows to fit the second tube 53 over the first tube 50thereby covering nozzles 51. An inner size of the second tube 53 isdimensioned such that an air gap remains between the tube 53 and thefirst tube 50 when the latter is inserted into the former. The end ofthe second tube 53 located near to the plate 4 is terminated by aturbine 54 which offers surfaces to the air stream 41 exiting theopening 52 of the first tube 50 such that the fixing means 53, 4, 5 andthe data carrier 1 are set in rotation. At the same time the second tube53 is lifted at a determined distance from the first tube 50 such thatit may freely rotate around the first tube 50. The centering means 21,23 guide the fixing means in the gyroscopic movement which is adoptedduring rotation of the data carrier 1.

What is claimed is:
 1. A device for rotating inside of a disk playerand/or recorder a disk shaped data carrier having an opening around acenter of said disk shaped carrier, said device comprising: fixing meansfor removably fixing said data carrier by inserting a part of saidfixing means in said opening, said fixing means having a rest positionassociated therewith; driving means for rotating said data carrier byacting on said fixing means, said driving means being at least partlymechanically connected to said disk player and/or recorder; and sidemoving means for allowing said fixing means to rotate about said restposition on a rotation plane substantially perpendicular to an axis ofrotation of said fixing means, the side moving means comprising aflexible transmission means through which said driving means acts onsaid fixing means, an end of said flexible transmission means beingconnected to said driving means and another end of said flexibletransmission means being connected to said fixing means.
 2. The deviceaccording to claim 1 wherein said moving means further comprises asliding support and said disk player and/or recorder comprises asupporting surface disposed parallel to said rotation plane, such thatsaid sliding support slides on said supporting surface, said slidingsupport having a drive opening through which said driving means acts onsaid fixing means.
 3. The device according to claim 2 wherein saidfixing means comprises an elongated part fitted through said driveopening together with a second bearing means which allow said elongatedpart to rotate inside said drive opening, said elongated part beingconnected to said another end of said flexible transmission means. 4.The device according to claim 3 further comprising centering means forpositioning said fixing means in a central position when said drivingmeans stops driving said data carrier.
 5. The device according to claim4, wherein said centering means comprises a conical recess whichreceives a tip shaped extremity from said fixing means, and iselastically mounted to said player and/or recorder.
 6. A device forrotating inside of a disk player and/or recorder a disk shaped datacarrier having an opening around a center of said disk shaped carrier,said device comprising: fixing means for removably fixing said datacarrier by inserting a part of said fixing means in said opening, saidfixing means having a rest position associated therewith; driving meansfor rotating said data carrier by acting on said fixing means; sidemoving means for allowing said fixing means to rotate about an axis ofsaid rest position on a rotation plane substantially perpendicular to anaxis of rotation of said fixing means; and scanning means for scanningsaid data carrier, said scanning means being mechanically connected tosaid disk player and/or recorder such that said axis of rotation of saidfixing means is able to move relative to said scanning means when saidfixing means rotates about said axis of said rest position.